Project Summary/Abstract: Ambulatory children with cerebral palsy (CP) demonstrate significant gait deviations (e.g., excessive hip/knee flexion in stance), which limits their walking activity and ability to physically participate in day to day life. Ankle Foot Orthoses (AFO) is a fundamental rehabilitation strategy to facilitate walking in children with CP; yet, efficacy in this population remains equivocal. The immediate positive effect of Ankle Foot Orthoses-Footwear Combinations (AFO-FC), a novel systematic decision tree for orthotic prescription for gait deviations in CP has been documented in the lab. Case series data has documented significant positive effects on gait speed, community walking activity and parent satisfaction for the AFO-FC. The underlying biomechanical mechanisms and clinical predictors of effect are unclear. The objective of this pilot study application is to examine the effect of AFO-FC on overall gait deviations and walking speed as compared to current AFO in children with CP. To identify potential biomechanical mechanisms, we will capture gait deviations during stance. We will examine the effect of the AFO-FC on balance, daily walking activity, physical activity and satisfaction. The premise of the AFO-FC approach, which incorporates a rigid AFO, is that individualized segment alignment and shoe modifications controls ankle movement and appears visually to enhance hip/knee extension during mid stance and commencement of terminal stance. We hypothesize that AFO-FC approach will decrease gait deviations in stance towards the alignment of typically developing children, which will positively affect gait speed, balance, community-based walking and physical activity. This hypothesis will be tested by the following specific aims. Aim 1: examine the effect of AFO-FC on overall gait deviations and walking speed as compared to current AFO in children with CP. We propose a randomized waitlist study of 22 ambulatory children with CP and bilateral barefoot midstance crouch gait, ages 4 to 9 years to compare currently prescribed AFO to the AFO- FC. Gait deviations and walking speed will be measured by instrumented three dimensional gait analyses. Aim 2: examine the effect of AFO-FC on daily walking activity, balance and satisfaction as compared to current AFO in children with CP Walking activity will be captured by the StepWatch accelerometer; balance with the Pediatric Balance Scale and physical activity and satisfaction through parental report questionnaires. This project is innovative because it focuses on a novel approach to individualized orthotic prescription employing a published decision tree in a heterogeneous population with a study design that leverages recruitment and retention. The proposed research is significant because it will be the first step in a continuum of research that is expected to direct orthotic prescription and rehab strategies across pediatric disabilities and positively effect changes in community-based walking activity for children with CP. Advances in the understanding of the biomechanical mechanisms by which children with CP respond to AFO-FC are expected with relevance to the health and functional benefits of enhanced mobility and physical activity across the life span.